An evaluation of CO2 and H2 selective polymeric membranes for CO2 separation in IGCC processes

The potential of CO2 and H2 selective polymeric membranes to separate CO2 from integrated coal gasification combined cycle power plants is examined. As a reference power plant a modified version of the Puertollano gasification plant has been defined. A detailed ASPEN model for the reference case has been developed. For the CO2 selective membranes single membrane module concepts as well as cascade concepts have been examined. The results for H2 and CO2 selective membranes show that with membranes of state of the art (CO2/H2 selectivity 15.5, H2/CO2 selectivity 5.91) the current requirements concerning CO2 purity and CO2 separation degree cannot be fulfilled. A CO2/H2 selectivity of 150 for a single CO2 selective membrane would be needed to obtain power plant efficiency losses below 10% points with separation degrees above 85%. For a cascade concept the CO2/H2 selectivity needed would be in the order of 60 to achieve the same values. For H2 selective membranes with a H2/CO2 selectivity of 50 separation degrees of 85% at efficiency losses below 10% points can be reached.